The invention relates to a drilling device in which the force is transmitted from a hollow-cylindrical drive member to a tubular shank equipped with a drill bit.
Applicant's own European Patent Application No. 0,235,581.A1 discloses a simplification and improvement of the coupling and efficiency of drilling devices operated with such a device in that a first coupling member and a second coupling member are equipped with hollow-cylindrical coupling regions which can be pushed into one another for coupling purposes; facing end faces of the two coupling members have clamping faces that are arranged perpendicularly to the axis of the drill pipe and can be pressed against one another; and the first coupling member is provided with projections while the second coupling member is provided with recesses, grooves or cutouts which engage in one another during coupling, and a clamping ring is provided on the first coupling member to produce the pressing effect. This clamping ring is rotatable by means of a screw connection that is disposed on the first coupling member and is thus mounted so as to be displaceable in the axial direction, with one end face of the clamping ring forming one of the clamping faces. This prior art arrangement has been found acceptable in practice.
It is also known to combine drilling devices with suction devices for the drill cuttings or with flushing devices. However, it has been found that drilling operations employing such prior art drilling devices must be interrupted frequently because the extraction paths become clogged.